Structure, Synthesis and Inhibition Mechanism of Nucleoside Analogues as HIV-1 Reverse Transcriptase Inhibitors (NRTIs)

Acquired immunodeficiency syndrome (AIDS) is caused by infection with the human immunodeficiency virus (HIV). Although treatments against HIV infection are available, AIDS remains a serious disease that causes many deaths annually. Although a variety of anti-HIV drugs have been synthesized and marketed to treat HIV-infected patients, nucleoside analogue reverse transcriptase inhibitors (NRTIs), which mimic nucleosides, are used extensively and remain a subject of interest to medicinal chemists. However, HIV has acquired drug resistance against NRTIs, and thus the struggle to find novel therapies continues. In this review, we trace the trajectory of NRTIs, focusing on the synthesis, mechanisms of action and applications of NRTIs that have been developed.

Experimental and computational studies on the effects of valganciclovir as an antiviral drug on calf thymus DNA

DNA-binding properties of an antiviral drug, valganciclovir (valcyte) was studied by using emission, absorption, circular dichroism, viscosity, differential pulse voltammetry, fluorescence techniques, and computational studies. The drug bound to calf thymus DNA (ct-DNA) in a groove-binding mode. The calculated binding constant of UV-vis, K_a, is comparable to groove-binding drugs. Competitive fluorimetric studies with Hoechst 33258 showed that valcyte could displace the DNA-bound Hoechst 33258. The drug could not displace intercalated methylene blue from DNA double helix. Furthermore, the induced detectable changes in the CD spectrum of ct-DNA as well as changes in its viscosity confirm the groove-binding mode. In addition, an integrated molecular docking was employed to further investigate the binding interactions between valcyte and calf thymus DNA.

Selective anti-herpesvirus agents

This review article focuses on the anti-herpesvirus agents effective against herpes simplex virus, varicella-zoster virus and cytomegalovirus, which have either been licensed for clinical use (idoxuridine, trifluridine, brivudin, acyclovir, valaciclovir, valganciclovir, famciclovir and foscarnet) or are under clinical development (CMX001 [the hexadecyloxypropyl prodrug of cidofovir], the helicase-primase inhibitor BAY 57-1293 [now referred to as AIC316], FV-100 [the valine ester of Cf 1743] and the terminase inhibitor letermovir [AIC246]).